ISO 17744

Plastics — Determination of specific volume as a function of temperature and pressure, pvT diagram — Piston apparatus method

ISO 17744:2004 describes procedures for determining the specific volume of plastics as a function of temperature and pressure in both the molten and solid states. The standard specifies the use of a piston-equipped apparatus in which the test sample, held in a measurement cell, is pressurized by means of the piston. Measurements under conditions of constant pressure or constant temperature can be made. In the constant-pressure mode, the maximum heating and cooling rates permissible are restricted to 5 °C/min. By using these procedures, it is possible to obtain: pvT diagrams that represent the relationship which exists between pressure, specific volume and temperature for a given material; compressibility and volumetric thermal-expansion coefficients; information on first-order and glass transitions as a function of temperature and pressure.

Plastiques — Détermination du volume spécifique en fonction de la température et de la pression, diagramme pvT — Méthode utilisant un appareil à piston

L'ISO 17744:2004 décrit les modes opératoires pour déterminer le volume spécifique des plastiques en fonction de la température et de la pression à l'état fondu et à l'état solide. La norme spécifie l'utilisation d'un appareil à piston dans lequel l'échantillon d'essai, maintenu dans une cellule de mesure, est mis sous pression au moyen du piston. Des mesurages dans des conditions de pression constante ou de température constante peuvent être effectués. Dans le mode à pression constante, les vitesses maximales admissibles de chauffage et de refroidissement sont limitées à 5 °C/min. En utilisant ces modes opératoires, il est possible d'obtenir: des diagrammes pvT qui représentent les relations entre la pression, le volume spécifique et la température d'un matériau donné; le coefficient de compressibilité et le coefficient de dilatation thermique volumétrique; la transition de premier ordre et la transition vitreuse en fonction de la température et de la pression.

General Information

• Status: Not Published
• ICS: 83.080.01 - Plastics in general
• Technical Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Drafting Committee: ISO/TC 61/SC 5 - Physical-chemical properties
• Current Stage: 6000 - International Standard under publication
• Start Date: 02-May-2025
• Completion Date: 03-May-2025

Relations

• Revises: ISO 17744:2004 - Plastics — Determination of specific volume as a function of temperature and pressure (pvT diagram) — Piston apparatus method
• Effective Date: 05-Nov-2022

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/FDIS 17744
ISO/TC 61/SC 5
Plastics — Determination of specific
Secretariat: DIN
volume as a function of temperature
Voting begins on:
and pressure, pvT diagram — Piston
2025-03-06
apparatus method
Voting terminates on:
2025-05-01
Plastiques — Détermination du volume spécifique en fonction
de la température et de la pression, diagramme pvT — Méthode
utilisant un appareil à piston
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 17744:2025(en) © ISO 2025

FINAL DRAFT
ISO/FDIS 17744:2025(en)
International
Standard
ISO/FDIS 17744
ISO/TC 61/SC 5
Plastics — Determination of specific
Secretariat: DIN
volume as a function of temperature
Voting begins on:
and pressure, pvT diagram — Piston
apparatus method
Voting terminates on:
Plastiques — Détermination du volume spécifique en fonction
de la température et de la pression, diagramme pvT — Méthode
utilisant un appareil à piston
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2025
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/FDIS 17744:2025(en) © ISO 2025

ii
ISO/FDIS 17744:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3  Terms and definitions . 1
4 Principle . 3
5 Apparatus . 4
5.1 General .4
5.2 Measurement cell .4
5.3 Piston .5
5.4 Temperature-regulating device .5
5.5 Test temperature measuring device .5
5.6 Device for measuring the distance travelled by the piston .5
5.7 Pressure-measuring device .6
5.8 Measurement system .6
5.9 Balance .6
6 Equipment calibration . 6
6.1 System .6
6.2 Measurement cell .6
6.3 Piston displacement measuring device .6
6.4 Test temperature .7
6.4.1 Location .7
6.4.2 Measurement of test temperature .7
6.4.3 Temperature calibration .7
7 Test sample . 7
7.1 Preparation .7
7.2 Conditioning.7
8 Procedure . 8
8.1 Preliminary phase .8
8.2 Measurements . .8
8.2.1 General .8
8.2.2 Isobaric measurements .8
8.2.3 Isothermal measurements .9
8.3 Final stage .9
8.4 Further measurements of density .9
9 Expression of results . 10
10 Precision . 10
11 Test report . 10
11.1 General and test conditions .10
11.2 Presentation of the results .11
Annex A (normative)  Sources of error when specific volume is measured as a function of
temperature and pressure .12
Annex B (informative) Examples of pvT diagrams . 14
Bibliography .18

iii
ISO/FDIS 17744:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 5,
Physical‑chemical properties.
This second edition cancels and replaces the first edition (ISO 17744:2004), which has been technically
revised.
The main changes are as follows:
— procedure for measuring amourphous samples with a lower height of the sample once melted has
been added;
— a specification for the balance to determine specific volume or density has been added;
— a specification for temperature calibration and position of measurement has been added;
— a specification for further measurement of density in the melt has been added;
— the presentation of results has been revised.
Any
...

2025-01
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ISO/FDIS 17744:2024(E)
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ISO /TC 61/SC 5/WG 9
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Secretariat: DIN
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Date: 2025-02-20
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Plastics — Determination of specific volume as a function of
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temperature and pressure, pvT diagram — Piston apparatus method
numbers
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Plastiques — Détermination du volume spécifique en fonction de la température et de la pression (, diagramme
pvT) — Méthode utilisant un appareil à piston
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ISO/FDIS 17744:2025(Een)
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spacing: single
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
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may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
Before: 0 pt, No page break before, Adjust space
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
between Latin and Asian text, Adjust space between
at the address below or ISO’s member body in the country of the requester.
Asian text and numbers
ISO copyright office
Formatted: Default Paragraph Font
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Formatted: French (Switzerland)
EmailE-mail: [e-mail]
Formatted: French (Switzerland)
Website: www.iso.orgwww.iso.org
Formatted: French (Switzerland)
Published in Switzerland
Formatted: French (Switzerland)
Formatted: English (United Kingdom)

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ii © ISO 2024 2025 – All rights reserved
ii
ISO/FDIS 17744:2025(Een)
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Formatted: HeaderCentered, Left, Space After: 0 pt,
Contents
Line spacing: single
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Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Apparatus . 5
6 Equipment calibration . 8
7 Test sample . 9
8 Procedure . 9
9 Expression of results . 11
10 Precision . 12
11 Test report . 12
Annex A (normative) Sources of error when specific volume is measured as a function of
temperature and pressure . 14
Annex B (informative) Examples of pvT diagrams . 16
Bibliography . 21

Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Apparatus . 4
5.1 General. 4
5.2 Measurement cell . 5
5.3 Piston . 5
5.4 Temperature-regulating device . 6
5.5 Test temperature measuring device . 6
5.6 Device for measuring the distance travelled by the piston . 6
5.7 Pressure-measuring device. 6
5.8 The measurement system . 7
6 Equipment calibration . 7
6.1 System . 7
6.2 Measurement cell . 7
Formatted: Font: 10 pt
6.3 Piston displacement measuring device . 7
Formatted: Font: 10 pt
6.4 Test temperature . 7
Formatted: Font: 11 pt
7 Test sample . 8
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7.1 Preparation . 8
pt, Line spacing: single
iii
ISO/FDIS 17744:2025(Een)
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7.2 Conditioning . 8
Formatted: HeaderCentered, Space After: 0 pt, Line
8 Procedure . 8
spacing: single
8.1 Preliminary phase . 8
8.2 Measurements . 9
1.1.1 Isobaric measurements . 9
2.1.1 Isothermal measurements . 9
8.3 Final stage . 10
8.4 Further measurements of density . 10
9 Expression of results . 10
10 Precision . 11
11 Test report . 11
11.1 General and test conditions . 11
11.2 Presentation of the results . 12
Annex A (normative) Sources of error when specific volume is measured as a function of
temperature and pressure . 13
A.1 Presence of voids, bubbles or heterogeneity in the test sample . 13
A.2 Sensor drift . 13
A.3 Friction . 13
A.4 Sensor compliance and apparatus expansion . 13
A.5 Non-uniformity of the temperature distribution . 14
A.6 Errors concerning the mass . 14
Annex B (informative) Examples of pvT diagrams . 15
Bibliography . 19

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iv © ISO 2024 2025 – All rights reserved
iv
ISO/FDIS 17744:2025(Een)
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Foreword
Line spacing: single
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ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obt
...